Technical Field
The present disclosure relates generally to precision metrology and, more particularly, to linear and rotary absolute electromagnetic position encoders.
Description of the Related Art
Position encoders (more particularly, induced current encoders) typically have a readhead that is movable relative to a scale member, and includes one or more transducers comprising a field generator (e.g., an excitation winding) and a field detector (e.g., receiver winding(s)). Typical absolute position encoders employ multiple parallel scale tracks juxtaposed with parallel sets of field generators and field detectors in the readhead to determine an absolute position.
U.S. Pat. No. 6,329,813, which is commonly assigned and hereby incorporated herein by reference in its entirety, discloses an absolute position encoder transducer employing multiple parallel scale tracks for determining an absolute position. While the '813 patent provides a high accuracy configuration, in some applications it is desirable to provide an absolute position encoder transducer which employs a more compact single scale track and a readhead comprising a set composed of a field detector and a field generator to determine an absolute position while further providing stronger position signals, a larger gap between the scale track and readhead, and/or lower power consumption.